Add randomness for post selection

src/wp-admin/includes/schema.php

@@ -563,6 +563,9 @@ function populate_options( array $options = array() ) {
 
 		// 6.9.0
 		'wp_notes_notify'                 => 1,
+
+		// 7.2.0
+		'wp_random_base'                  => '',
 	);
 
 	// 3.3.0

src/wp-admin/includes/upgrade.php

@@ -2892,7 +2892,7 @@ function __get_option( $setting ) { // phpcs:ignore WordPress.NamingConventions.
 		return __get_option( 'siteurl' );
 	}
 
-	if ( in_array( $setting, array( 'siteurl', 'home', 'category_base', 'tag_base' ), true ) ) {
+	if ( in_array( $setting, array( 'siteurl', 'home', 'category_base', 'tag_base', 'wp_random_base' ), true ) ) {
 		$option = untrailingslashit( $option );
 	}
 

src/wp-admin/network/site-settings.php

@@ -162,6 +162,7 @@
 				'permalink_structure',
 				'category_base',
 				'tag_base',
+				'wp_random_base',
 				'upload_path',
 				'upload_url_path',
 			);

src/wp-admin/options-permalink.php

@@ -69,6 +69,9 @@
 get_current_screen()->set_help_sidebar( $help_sidebar_content );
 unset( $help_sidebar_content );
 
+/** @global WP_Rewrite $wp_rewrite WordPress rewrite component. */
+global $wp_rewrite;
+
 $home_path           = get_home_path();
 $iis7_permalinks     = iis7_supports_permalinks();
 $permalink_structure = get_option( 'permalink_structure' );
@@ -94,6 +97,8 @@
 
 $category_base = get_option( 'category_base' );
 $tag_base      = get_option( 'tag_base' );
+$random_base   = get_option( 'wp_random_base' );
+$random_base   = is_string( $random_base ) ? $random_base : '';
 
 $structure_updated        = false;
 $htaccess_update_required = false;
@@ -144,6 +149,16 @@
 
 		$wp_rewrite->set_tag_base( $tag_base );
 	}
+
+	if ( wp_is_random_content_redirect_enabled() && isset( $_POST['wp_random_base'] ) && is_string( $_POST['wp_random_base'] ) ) {
+		$random_base = $_POST['wp_random_base'];
+
+		if ( ! empty( $random_base ) ) {
+			$random_base = $blog_prefix . preg_replace( '#/+#', '/', '/' . str_replace( '#', '', $random_base ) );
+		}
+
+		$wp_rewrite->set_random_base( $random_base );
+	}
 }
 
 if ( $iis7_permalinks ) {
@@ -236,6 +251,7 @@
 	$permalink_structure = preg_replace( '|^/?blog|', '', $permalink_structure );
 	$category_base       = preg_replace( '|^/?blog|', '', $category_base );
 	$tag_base            = preg_replace( '|^/?blog|', '', $tag_base );
+	$random_base         = preg_replace( '|^/?blog|', '', $random_base ) ?? '';
 }
 
 $url_base = home_url( $blog_prefix . $index_php_prefix );
@@ -457,6 +473,29 @@ class="button button-secondary"
 		<?php endif; ?>
 		</td>
 	</tr>
+	<?php if ( wp_is_random_content_redirect_enabled() ) : ?>
+	<tr>
+		<th>
+			<label for="wp_random_base">
+				<?php _e( 'Random base' ); ?>
+			</label>
+		</th>
+		<td>
+		<?php if ( '' === $blog_prefix ) : ?>
+			<input name="wp_random_base" id="wp_random_base" type="text"
+				value="<?php echo esc_attr( $random_base ); ?>" class="regular-text code"
+			/>
+		<?php else : ?>
+			<span class="code permalink-structure-has-blog-prefix">
+				<code class="no-break"><?php echo $blog_prefix; ?></code>
+				<input name="wp_random_base" id="wp_random_base" type="text"
+					value="<?php echo esc_attr( $random_base ); ?>" class="regular-text code"
+				/>
+			</span>
+		<?php endif; ?>
+		</td>
+	</tr>
+	<?php endif; ?>
 	<?php do_settings_fields( 'permalink', 'optional' ); ?>
 </table>
 

src/wp-includes/class-wp-post-type.php

@@ -123,6 +123,19 @@ final class WP_Post_Type {
 	 */
 	public $embeddable = null;
 
+	/**
+	 * Whether posts of this post type can be selected by random content redirects.
+	 *
+	 * Random content redirects send requests such as `example.com/random/` to a
+	 * randomly selected post.
+	 *
+	 * Default is true when $publicly_queryable is true and the post type has an archive.
+	 *
+	 * @since 7.2.0
+	 * @var bool $randomable
+	 */
+	public $randomable = null;
+
 	/**
 	 * Whether to generate and allow a UI for managing this post type in the admin.
 	 *
@@ -535,6 +548,7 @@ public function set_props( $args ) {
 			'exclude_from_search'             => null,
 			'publicly_queryable'              => null,
 			'embeddable'                      => null,
+			'randomable'                      => null,
 			'show_ui'                         => null,
 			'show_in_menu'                    => null,
 			'show_in_nav_menus'               => null,
@@ -578,6 +592,9 @@ public function set_props( $args ) {
 		// If not set, default to the setting for 'public'.
 		$args['embeddable'] ??= $args['public'];
 
+		// If not set, default to publicly queryable post types with an archive.
+		$args['randomable'] ??= $args['publicly_queryable'] && (bool) $args['has_archive'];
+
 		// If not set, default rest_namespace to wp/v2 if show_in_rest is true.
 		if ( false === $args['rest_namespace'] && ! empty( $args['show_in_rest'] ) ) {
 			$args['rest_namespace'] = 'wp/v2';

src/wp-includes/class-wp-query.php

@@ -417,6 +417,16 @@ class WP_Query {
 	 */
 	public bool $is_sitemap = false;
 
+	/**
+	 * Signifies whether the current query is for random content.
+	 *
+	 * True for a blog home, archive or search request that includes the `random`
+	 * query variable, for example `example.com/random/` or `example.com/?s=foo&random`.
+	 *
+	 * @since 7.2.0
+	 */
+	public bool $is_random = false;
+
 	/**
 	 * Signifies whether the current query is for the page_for_posts page.
 	 *
@@ -527,6 +537,7 @@ private function init_query_flags() {
 		$this->is_robots            = false;
 		$this->is_favicon           = false;
 		$this->is_sitemap           = false;
+		$this->is_random            = false;
 		$this->is_posts_page        = false;
 		$this->is_post_type_archive = false;
 	}
@@ -1147,6 +1158,10 @@ public function parse_query( $query = '' ) {
 
 		$this->is_embed = $this->is_embed && ( $this->is_singular || $this->is_404 );
 
+		$this->is_random = isset( $query_vars['random'] )
+			&& ! $this->is_feed
+			&& ( $this->is_home || $this->is_archive || $this->is_search );
+
 		$this->query_vars_hash    = md5( serialize( $this->query_vars ) );
 		$this->query_vars_changed = false;
 
@@ -4653,6 +4668,19 @@ public function is_sitemap(): bool {
 		return $this->is_sitemap;
 	}
 
+	/**
+	 * Determines whether the query is for random content.
+	 *
+	 * @since 7.2.0
+	 *
+	 * @see wp_is_random_content_query()
+	 *
+	 * @return bool Whether the query is for random content.
+	 */
+	public function is_random(): bool {
+		return $this->is_random;
+	}
+
 	/**
 	 * Determines whether the query is for a search.
 	 *